Thermal imaging device

Abstract

A pyroelectric film has a pattern of interconnected electrodes formed on one major surface, and a pattern of discrete electrodes and electrically conductive contacts formed on the other major surface. Each discrete electrode is connected to a respective contact by a respective strip of electrically conductive material. Regions of the film each including a contact and part of the associated strip are formed in tongues pulled out of the plane of the film. The contacts are thus able to make electrical contact with respective input terminals of an integrated circuit.

I claim: 
     
       1. A thermal imaging device comprising: a layer comprising pyroelectric material; an array of discrete electrodes carried on one major surface side of the layer; an array of interconnected electrodes carried on the other major surface of the layer so as to define with the layer and discrete electrodes an array of pyroelectric detector elements; an array of electrically conductive contacts carried on said one surface of the layer, each conductive contact being connected to a respective discrete electrode by an elongate electrically conductive strip, portions of the layer each carrying at least one contact and part of the associated conductive strip being formed into tongues attached to the major portion of the layer along only part of their peripheries, the free ends of the tongues being pulled out of the plane of the layer, each contact being electrically connected to a respective input of a signal processing means. 
     
     
       2. A device according to claim 1 in which the arrays of discrete electrodes and contacts are intercalated. 
     
     
       3. A device according to claim 1 in which each tongue carries two contacts. 
     
     
       4. A device according to claim 1 in which further tongues are formed in the layer, the further tongues being pulled out of the plane of the layer in the opposite direction to the tongues carrying the contacts, the two sets of tongues together locating the pyroelectric detector array in a housing. 
     
     
       5. A device according to claim 1 in which the tongues or further tongues are formed with an enlarged portion at the end attached to the major portion of the layer. 
     
     
       6. A device according to claim 1 in which the layer is a flexible film. 
     
     
       7. A device according to claim 6 in which the pyroelectric material is polyvinylidene fluoride or a copolymer of vinylidene. 
     
     
       8. A device according to claim 1 in which the layer is a composite layer comprising pyroelectric material carried on a flexible substrate. 
     
     
       9. A device according to claim 8 in which at least part of the tongues do not carry pyroelectric material.